This invention relates in general to flexible boots for protecting objects from contamination from moisture and dirt. In particular, this invention relates to an improved structure for such a flexible boot for protectively covering a joint between two relatively movable, torque transmitting devices, such as a slip yoke assembly adapted for use in a vehicle drive train assembly.
In most land vehicles in use today, a drive train assembly is provided for transmitting rotational power from an output shaft of an engine/transmission assembly to an input shaft of an axle assembly so as to rotatably drive one or more wheels of the vehicle. To accomplish this, a typical vehicular drive train assembly includes a hollow cylindrical driveshaft tube. A first universal joint is connected between the output shaft of the engine/transmission assembly and a first end of the driveshaft tube, while a second universal joint is connected between a second end of the driveshaft tube and the input shaft of the axle assembly. The universal joints provide a rotational driving connection from the output shaft of the engine/transmission assembly through the driveshaft tube to the input shaft of the axle assembly, while accommodating a limited amount of angular misalignment between the rotational axes of these three shafts.
Not only must the drive train assembly accommodate a limited amount of angular misalignment between the engine/transmission assembly and the axle assembly, but it must also typically accommodate a limited amount of axial movement between the engine/transmission assembly and the axle assembly. A small amount of such relative axial movement frequently occurs when the vehicle is operated. To address this, it is known to provide one or more slip yoke assemblies in the drive train assembly. A typical slip yoke assembly includes first and second splined members that are connected to respective components of the drive train assembly. The splined members provide a rotational driving connection transmitting torque from one torque from one component of the drive train assembly to another, while permitting a limited amount of axial movement between the components. In some instances, the first splined member may be provided on the end of a yoke connected to a universal joint assembly, while the second splined member may be connected to a driveshaft section of the drive train assembly.
As is well known in the art, most slip yoke assemblies are provided with sealing structures to prevent the entry of dirt, water, and other contaminants into the region where the splined members engage one another. Such contaminants can adversely affect the operation of the slip yoke assembly and cause premature failure. A number of sealing structures are known in the art for use with conventional slip yoke assemblies. Both exterior and interior sealing structures are typically be provided to fully protect the region where the splined members engage one another. Exterior sealing structures are disposed about the exterior of the slip yoke assembly and prevent contaminants from entering into this region from the exterior environment. Interior sealing structures are disposed within the slip yoke assembly and prevent contaminants from entering into this region through the hollow yokes or driveshaft sections connected to the splined members.
A typical exterior sealing structure for a slip yoke assembly is a boot that is formed having a series of convolutions of flexible material. One end of the boot is connected to the shaft of the slip yoke, while the other end of the boot is connected to the exterior of the corresponding slip shaft. The convolutions in the boot give it the ability to expand as necessary to accommodate the relative axial movement between the slip yoke and the slip shaft. The flexible boot usually has an annular groove molded into each end of the boot to receive an annular clamping band for securely engaging the boot with the slip yoke and slip shaft. Although the annular groove is provided for positively seating the band clamp, the band clamp is often difficult to install properly on the boot during assembly of the slip yoke assembly. Thus, it would be advantageous if there could be developed an improved structure for such a flexible boot that would facilitate the proper installation of the boot and band clamp.
This invention relates to an improved structure for a protective boot, wherein the boot includes a flexible, generally cylindrical main body and at least one generally cylindrical clamping end having a plurality of loops spaced circumferentially about the clamping end. The loops are shaped to receive a band clamp and retain the band clamp in position with respect to the clamping end, thereby making it easier to assemble the boot on the object to be protected. The clamping end may have a groove for receiving the band clamp, with the loops comprising generally flat webs bridging the groove and spaced circumferentially about the clamping end. In another embodiment of the invention, there is provided a torque transmitting device including a first drive member and a second drive member both mounted for rotation about a common axis. One of the drive members is axially movable with respect to the other, and the two drive members are engaged with each other for transmitting torque from one drive member to the other. A boot having a flexible, generally cylindrical main body and a generally cylindrical first clamping end is positioned about one of the drive members. The first clamping end has a plurality of loops spaced circumferentially about the first clamping end. The loops are shaped to receive a band clamp and to retain the band clamp in position with respect to the first clamping end. In yet another embodiment of the invention there is provided a slip yoke assembly for a vehicle drive train assembly. The slip yoke assembly includes a yoke shaft having an externally splined shaft portion, and a slip shaft having a hollow internally splined portion disposed co-axially about the shaft portion of the yoke shaft. The yoke shaft and the slip shaft are axially movable with respect to each other and are engaged with each other for transmitting torque from one to the other. Two band clamps, and a boot are provided. The boot has a first clamping end positioned about the yoke shaft and a second clamping end positioned about the slip shaft. The first clamping end has a plurality of loops spaced circumferentially about the first clamping end. The loops are shaped to receive a band clamp and to retain the band clamp in position with respect to the first clamping end. The second clamping end has a plurality of loops spaced circumferentially about the second clamping end. The loops are shaped to receive a band clamp and to retain the band clamp in position with respect to the second clamping end.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.